Half-shells without a hole, made of raw Steel—semi-circular domed shells (semi-circular shells) in 14 sizes with nominal diameters ranging from 21.3 to 159 mm. Material thicknesses from 1.5 to 4.0 mm, heights from 5 to 26 mm, weights from 0.01 to 0.65 kg. Designated by Ø, material thickness S, and Height H. Closed, unperforated design without an opening.